The present invention relates to pest control, and more particularly to monitoring termite activity proximate and especially under building structures.
Termite infestation and damage is a continuing problem in buildings having wood structure. Traditionally, the structures are inspected only infrequently, such as in connection with a sale, at which time considerable damage may have been done, with expensive repairs being required. Termite infestation and damage is generally not readily apparent, and partial dismantling of building structures in order to locate possible infestation has to be weighed against the damage done by such dismantling and the cost of restoration. Even professional inspections are not always effective with respect to inaccessible structure.
Accordingly, various non-invasive devices have been developed for detecting termite activity, such devices being implanted in the ground around and/or under homes or other building structures. For example, U.S. Pat. No. 5,329,726 to Thorne et al. and U.S. Pat. No. 5,901,496 to Woodruff disclose ground-implantable devices for detecting termite activity, the devices having a perforate outer housing for permanent ground implantation, and a removable perforate cartridge having bait therein. The cartridge is removed and visually inspected for detection of termite activity. These devices of the prior art exhibit a number of disadvantages; for example:
1. They are ineffective in that active termite infestations may be ignored because:
a. the unit does not get proper inspections;
b. the original placement of the unit is difficult to determine;
c. an aggressive termite colony was not identified early; and
2. They are difficult to install and monitor, especially when implanted in crawl space under structures.
Thus there is a need for a device that facilitates detection and monitoring of infestation of soil environments of building structures by destructive organisms, that is both effective and easy to use, and that is inexpensive to provide.
The present invention meets this need by providing a monitoring device having a direct indication of a predetermined amount of cumulative destructive activity of invasive organisms such as termites. In one aspect of the invention, an apparatus for signaling a cumulative amount of weakening of a test material resulting from exposure to a hazardous environment includes a body; a test element supported relative to the body and comprising the test material; means for controllably exposing the test element to the hazardous environment; means for applying a load force to the test element, the load force being effective for displacing a portion of the test element when there is a predetermined amount of weakening of the test element; a flag member movably supported relative to the body and coupled to the test element for movement in projecting relation to the body when the test element is weakened to the predetermined amount. The means for controllably exposing can include the body having a cavity for enclosing the test element, a side wall of the body having an opening therein for communicating with the hazardous environment. As used herein xe2x80x9chazardous environmentxe2x80x9d means an environment that may be deleterious to the strength of a structural material.
In another aspect of the invention, an apparatus for detecting the presence and eating activity of organisms that damage structures by consuming portions thereof includes the body; a bait element supported relative to the body and comprising a consumable structural material; means for controllably exposing the bait element to the organisms; means for applying a load force to the bait element, the load force being effective for displacing a portion of the bait element when there is a predetermined amount of weakening of the bait element; a flag member movably supported relative to the body and coupled to the bait element for movement in projecting relation to the body when the bait element is weakened to the predetermined amount by the organisms.
The exposing means can include the body having a cavity for enclosing the bait element, a side wall of the body having an entrance passage formed therein for admitting the organisms. Preferably the exposing means further includes a barrier member covering the entrance passage and being formed of a sheet of consumable porous material for excluding foreign material from the entrance passage. The consumable material of the barrier member is preferably perforated for enhanced communication of bait odor out of and of the organisms into the entrance passage. The barrier member can also act as an attractant, being selected, for example, from the group consisting of balsa wood, pine, and cardboard. Preferably the body has an outer portion to which the sheet of consumable porous material is connected and a telescopically separable core portion that supports the bait element and the flag member for facilitating removal and inspection of the bait element without disturbing the outer body and the sheet of porous material.
The entrance passage can extend between a first opening in an outside surface of the side wall and a second opening in an inside surface of the side wall, the first opening having a first area, the second opening having a second area being preferably less than the first area, the passage smoothly tapering between the first area and the second area for concentrating eating activity at a specific location along the bait element. The body can form an elongate housing having respective bottom and top extremities, the entrance passage being preferably one of a vertically spaced plurality of entrance passages for exposure to organisms at plural depths within the hazardous environment, a consumable porous barrier member covering each of the entrance passages. The entrance passages and the barrier member can be on a first fade of the body, the body preferably including a second face having counterparts of the entrance passages and the barrier member for exposing the bait element to organisms approaching from different directions.
The means for applying a load force can include a first coupling for anchoring one end to the bait element to the body, a second coupling for connecting an opposite end of the bait element, and a spring for applying tensile load to the bait element through the second coupling. The flag member can be connected to the second coupling. The bait element can be a wood member having a bait substance applied thereto.
In a further aspect of the invention, a method for monitoring a predetermined cumulative eating activity of organisms on a bait member includes:
(a) providing a housing body having an elongate cavity and a side wall passage;
(b) anchoring one end of the bait member to the body with the bait member extending within the cavity;
(c) connecting a flag member to an opposite end of the bait member with the flag member extending to proximate a flag opening of the body;
(d) connecting a spring member between the flag member and the housing body for tensioning the bait member;
(e) placing the housing body in a medium subject to infestation by the organisms with the side wall passage being accessible by the organisms and the flag opening being located outside the medium; and
(f) periodically observing the housing body for display to the flag member in an extended position thereof.
The method can further include interposing a consumable porous barrier between the medium and the side wall passage for preventing the medium from contacting the bait member.